Describing the language of a given DFA

Question

I am do not see how I could find the regular expression of the language of the DFA below. It is clear that it has to look something like

$$b \cup (a...)$$

but I do not see how to describe the "lower path". Could you help me?

Answer 1

Setting $A = \{a,b\}$, your language can be written as $b(A^2)^* + aA(A^2)^*$.